1. Field of the Invention
The present invention relates to an apparatus for manufacturing an electron source used for a display panel or the like and a method of manufacturing the electron source.
2. Related Background Art
Conventionally, as an electron-emitting device, there are generally known two types, namely, a thermoelectron-emitting device and a cold-cathode electron-emitting device. The cold-cathode electron-emitting device includes a field-emission electron-emitting device, a metal/insulator/metal electron-emitting device and a surface conduction electron-emitting device.
For example, there are surface conduction electron-emitting devices that utilize the phenomenon in which electron emission is caused by allowing an electric current to flow in a thin film formed with a small area on a substrate and in parallel to the film surface. Its basic structure and manufacturing method are disclosed, for example, in Japanese Patent Application Laid-Open No. H7-235255, and Japanese Patent Application Laid-Open No. H8-171849.
The surface conduction electron-emitting device is characterized by including on a substrate a pair of device electrodes opposing each other and an electroconductive film that is connected to the pair of device electrodes and has an electron-emitting region in a part thereof. In addition, a fissure is formed in a part of the electroconductive film and a deposited film containing at least one of carbon and a carbon compound as a main component is formed at the end of the fissure.
A plurality of such electron-emitting devices are arranged on a substrate and are connected to one another by wirings, whereby an electron source provided with the plurality of electron-emitting devices can be manufactured. In addition, a display panel of an image-display apparatus can be manufactured by combining the electron source with a phosphor.
When the electron source is manufactured, for example, a plurality of electroconductive members are formed on a substrate, and the substrate is placed on a support member having a cooling unit and covered with a vacuum chamber. The vacuum chamber includes a closed space formed by the support member and the vacuum chamber using a seal member such as a packing.
Next, after the vacuum chamber is exhausted, a voltage is applied to each of the electroconductive members through external terminals under a depressurized atmosphere to form an electron-emitting region in each of the electroconductive members. At the application of the voltage, heat generated from the substrate is recovered by the support member having the cooling unit.
According to a conventional manufacturing method, a temperature control performed by the support member is an open control. For example, a cooling medium having a predetermined temperature is allowed to flow into the cooling unit of the support member or a temperature of the cooling medium is changed so as to obtain a preset temperature profile.
However, when performances, such as an electron-emitting characteristic and a life, of the manufactured electron source are to be improved, it is necessary to control a temperature of the surface of the substrate with higher precision. In particular, when a variation in resistances of the electroconductive members or wirings connected with the electroconductive members is changed for each substrate, the quantity of heat generated from the surface of the substrate during an electron source manufacturing process is also changed for each substrate. Therefore, it is also required to control the temperature of the surface of the substrate to a predetermined temperature in consideration of the change in the quantity of heat generated.